motor_test.ino

const int PIN_MOTOR_FORWARD = 9;
const int PIN_MOTOR_BACKWARD = 10;

void setup () {
    pinMode(PIN_MOTOR_FORWARD, OUTPUT);
    pinMode(PIN_MOTOR_BACKWARD, OUTPUT);
}

void loop () {
    analogWrite(PIN_MOTOR_FORWARD, 125);
    analogWrite(PIN_MOTOR_BACKWARD, 0);
    delay(1000);
    analogWrite(PIN_MOTOR_FORWARD, 0);
    analogWrite(PIN_MOTOR_BACKWARD, 125);
    delay(1000);
    analogWrite(PIN_MOTOR_FORWARD, 0);
    analogWrite(PIN_MOTOR_BACKWARD, 0);
    delay(1000);
}